The DS1307 RTC I²C Module is a real-time clock module designed to keep accurate time and date even when the main system power is turned off. Using a backup coin-cell battery, it maintains seconds, minutes, hours, day, date, month, and year information. Its simple I²C interface makes it ideal for clocks, data loggers, and time-based automation projects.
Core Module Specifications
• RTC IC: DS1307
• Timekeeping: Seconds, minutes, hours, day, date, month, year
• Time Format: 12-hour / 24-hour selectable
• Backup Support: External coin cell battery (CR2032)
Electrical & Interface
• Operating Voltage: 5 V
• Logic Level: 5 V (I²C compatible with 3.3 V controllers using pull-ups)
• Communication Interface: I²C
• I²C Address: 0x68
• Interface Pins: VCC, GND, SDA, SCL
Performance Characteristics
• Maintains time during power loss using battery backup
• Accuracy dependent on external 32.768 kHz crystal
• Automatic leap year compensation
• Low power consumption in battery mode
Physical Characteristics
• Module Type: PCB-mounted RTC module
• Battery Holder: CR2032 coin cell slot
• Compact and lightweight design
Compatibility
• Arduino Uno / Nano / Mega
• ESP8266 / ESP32
• STM32, AVR, PIC microcontrollers
• Raspberry Pi (I²C interface)
Key Advantages
• Reliable timekeeping with battery backup
• Simple I²C communication
• Widely supported by libraries
• Easy integration in embedded projects
Technical Insights
• Requires external 32.768 kHz crystal for timing
• Battery not included with most modules
• Accuracy can drift slightly over long periods
• For higher accuracy, DS3231 is an alternative
Applications
• Digital clocks
• Data logging systems
• Time-stamped measurements
• Automation and scheduling
• Embedded and IoT projects
Pro Tip
• Insert the coin cell battery before setting time
• Set time once and avoid resetting on every boot
• Keep module away from heat sources for better accuracy
Package Includes
• 1 × DS1307 RTC I²C Module